The WHO Guidelines on Hand Hygiene in Health Care provide health-care workers (HCWs), hospital administrators and health authorities with a thorough review of evidence on hand hygiene in health care and specific recommendations to improve practices and reduce transmission of pathogenic microorganisms to patients and HCWs.

This Addendum to the second edition of the Guidelines for drinking-water quality contains reviews of a number of pathogens that occur widely in water - Aeromonas and Legionella spp., Vibrio cholerae, enteric hepatitis viruses, and protozoan parasites (Cryptosporidium, Giardia, and Cyclospora spp.). These review documents supersede, and are more comprehensive than, those previously published in Volumes 1 and 2 of the Guidelines.